package com.cdream.basic.util;

import cn.hutool.core.net.NetUtil;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import java.net.*;
import java.util.Enumeration;
import java.util.LinkedList;
import java.util.List;

/**
 * IP地址
 */
public class IPUtil {

	private static Logger logger = LoggerFactory.getLogger(IPUtil.class);

	/**
	 * 获取IP地址
	 * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
	 * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
	 */
	public static String getIpAddr() {
		String ip = null;
		try {
			HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
			ip = request.getHeader("x-forwarded-for");
			if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
				ip = request.getHeader("Proxy-Client-IP");
			}
			if (StringUtils.isEmpty(ip) || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
				ip = request.getHeader("WL-Proxy-Client-IP");
			}
			if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
				ip = request.getHeader("HTTP_CLIENT_IP");
			}
			if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
				ip = request.getHeader("HTTP_X_FORWARDED_FOR");
			}
			if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
				ip = request.getRemoteAddr();
			}
		} catch (Exception e) {
			logger.error("IPUtil ERROR ", e);
		}
		// 使用代理，则获取第一个IP地址
		if (StringUtils.isNotEmpty(ip) && ip.length() > 15) {
			if (ip.indexOf(",") > 0) {
				ip = ip.substring(0, ip.indexOf(","));
			}
		}
		return ip;
	}

	public static void main(String[] args) throws UnknownHostException, SocketException {
		// System.out.println(InetAddress.getLocalHost().getHostAddress());
		// System.out.println(getIpAddress());
		// System.out.println(getIpAddress2());
		System.out.println(NetUtil.getLocalHostName());
		System.out.println(NetUtil.getLocalhost());
		System.out.println(NetUtil.getLocalhostStr());
		System.out.println(NetUtil.localIps());

	}
	private static List<String> getIpAddress() throws SocketException {
		List<String> list = new LinkedList<>();
		Enumeration enumeration = NetworkInterface.getNetworkInterfaces();
		while (enumeration.hasMoreElements()) {
			NetworkInterface network = (NetworkInterface) enumeration.nextElement();
			if (network.isVirtual() || !network.isUp()) {
				continue;
			} else {
				Enumeration addresses = network.getInetAddresses();
				while (addresses.hasMoreElements()) {
					InetAddress address = (InetAddress) addresses.nextElement();
					if (address != null && (address instanceof Inet4Address || address instanceof Inet6Address)) {
						list.add(address.getHostAddress());
					}
				}
			}
		}
		return list;
	}

	private static List<String> getIpAddress2() throws SocketException {
		List<String> list = new LinkedList<>();
		Enumeration enumeration = NetworkInterface.getNetworkInterfaces();
		while (enumeration.hasMoreElements()) {
			NetworkInterface network = (NetworkInterface) enumeration.nextElement();
			Enumeration addresses = network.getInetAddresses();
			while (addresses.hasMoreElements()) {
				InetAddress address = (InetAddress) addresses.nextElement();
				if (address != null && (address instanceof Inet4Address || address instanceof Inet6Address)) {
					list.add(address.getHostAddress());
				}
			}
		}
		return list;
	}
}
